Keto-enol tautomerization is a constitutional-isomer equilibrium in organic chemistry in which a carbonyl compound (aldehyde or ketone) interconverts with an enol — an alkene bearing a hydroxyl group — by transfer of an alpha proton from the carbon adjacent to the carbonyl together with a shift of the pi bond between C=O and C=C. Tautomers are distinct molecules connected by bond reorganization, not resonance contributors of a single structure, and the interconversion requires acid or base catalysis, proceeding through a protonated carbonyl intermediate in acid or through the resonance-stabilized enolate anion in base. The topic belongs to carbonyl chemistry within organic reaction mechanisms, and it underpins alpha-carbon reactivity, enolate chemistry, and the stereochemical consequence that an sp3 alpha stereocenter is destroyed on enolization, permitting racemization.
Keto-enol tautomerization is a constitutional-isomer equilibrium in organic chemistry in which a carbonyl compound (aldehyde or ketone) interconverts with an enol — an alkene bearing a hydroxyl group…